Intracranial hemorrhage occurs commonly in very-low-birthweight babies, and may account for many of the developmental handicaps seen in graduates of neonatal intensive care units. The goal of this case-control study of germinal matrix hemorrhage in very-low-birthweight babies is to identify exposures and characteristics (of the babies and their mothers) which if eliminated or modified might result in a reduction in the occurence of this disorder. Subjects will have been admitted to the neonatal intensive care units at Children's Hospital, the Brigham and Women's Hospital, and the Beth Israel Hospital, weigh less than 1.75 kilograms at birth, and had an ultrasonogram. Cases for each study will have documented evidence if germinal matrix hemorrhage. Controls will have sonographic evidence that they do not have germical matrix hemorrhage. Data about antenatal risk factors will be obtained from interviews of mothers and review of obstetricians' office records. Information about perinatal variables will be obtained from detailed review if delivery and neonatal intensive care unit charts. Data analysis will incluse multivariate techniques, some of which employ models with variables entered in a temporal sequence) i.e., antenatal, then delivery variables, then postnatal variables in theorder in which they occurred). Many of the hypotheses to be tested, especially those about antenatal risk factors have been generated in studies of hemorrhages on babies who died. This proposal is unique in emphasizing antenatal factors and in routinely obtaining detailed information from mothers, usually before the existence or absence if a hemorrhage has been established.